Photothermal Therapy For Tumor Based On Magnetosomes Magnetic Targeting

Magnetosomes is a kind of magnetic nanoparticles synthesized by magnetotactic bacteria.Moreover,with the properties of similar particle size,monodispersity,high crystallinity,good biocompatibility,the magnetosomes were widely used in targeted drugs,early diagnosis of diseases,magnetic thermotherapy,medical imaging contrast agent,information recording materials and so on.In recent years,magnetic nanomaterial mediated photothermal therapy arouse increasingly attractive for researchers.In this study,magnetosomes were used for magnetic targeted drug delivery and photothermal therapy,demonstrate the potential of magnetosomes being used in the treatment of a range of tumors.The main works in this thesis is divided into three parts.1.Extraction of magnetosomes and study on its characteristics.Magnetotactic Bacteria were grown microaerobically in enriched magnetic spirillum growth medium and collected by centrifugation,they were crushed using ultrasonication through an ultrasonic generator.The high-resolution transmission electron microscope was performed to observe the magnetotactic bacteria AMB-1 and magnetosomes.The characteristics of particle size distribution and magnetic lattice are also analyzed.The cells were cultured with magnetosomes and cell viability were observed by CCK-8 assay.The results showed that when the concentration of magnetosomes reached 100 mg/mL,the viability rate of cells could reach more than 80%.2.Magnetic targeting with magnetosomes in vitro.The magnetic field is simulated by COMSOL Multiphysics software.An apparatus simulating bloodstream in the tumor was used to test the magnetic targeting of BMPs in vitro.It is found that the retention effect of magnetosomes is obvious when the model is 0-5 mm away from the pole of the magnet.Moreover,the retention effect of magnetosomes is significantly higher than synthetic magnetic particles.3.Photothermal therapy in vivo.Subcutaneous injection of H22 tumor cells into ICR mice.Magnetosomes injected through the caudal vein when the volume of tumor reached150-200 mm~3.The mice in the experimental group were treated with magnetic field,detect the magnetosomes content in tumor area and photothermal therapy.The photothermal therapy were repeated at next day and the third day.Mice tumor disappeared completely after treatment.In conclusion,magnetosomes can be used for photothermal treatment of tumor and has good biocompatibility.Magnetic field can increase the concentration of magnetosomes in the tumor and improve the efficiency of photothermal therapy.This thesis provides a new potential method for cancer treatment.